This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Uropathogenic E. Coli establish colonies in human urinary tract via its numerous pili on its surface. It is of significant biological and medical importance to study how the pili are formed. At the core of pilus biogenesis is the outer membrane protein usher PapC that not only transport the pilus subunit (pilin) out of the cell, but also serve as the platform for helical pilus assembly. We have previously determined a projection structure of the PapC usher by electron crystallography and 2D crystals. We are now pursuing x-ray crystallographic study. 3D crystals have been formed that we know are protein crystals. But we don't know how good the PapC crystals diffract. Thus the crystal info is unkown.